What if... the umbilical chord was strangling the baby before labor?

Last night my baby moved into a very strange position. Now, first of all, I am 35 weeks pregnant, so my baby is now taking up every possible inch of space, it seems. When he shifted into this position it was not only very uncomfortable for me, but it also made me worry because it seemed he could have just "fallen" into this position with my movements and I hadn't felt any fetal movement for a while, he seemed like he could be limp.
Personally, my boyfriend and I were both born with our umbilical chords wrapped around our necks and I guess I have this fear of that happening not just to my unborn child, but a fear that it's possible and how would anybody know until it's too late sometimes? I mean, I know it usually happens during labor (like it did with Steve and I), but it could happen at any time in the pregnancy since the babies all move around the entire time.
Anyways, I had built up a concern that my baby MIGHT be in trouble and I kept thinking, if I call the doctor they're probably just going to tell me everything is fine, not to worry, to trust the doctors, and go back to sleep. But I also felt like I shouldn't ignore that kind of concern... I mean, WHAT IF he really had been in trouble? I did go back to sleep, though... I truly think I made the wrong decision... luckily, he is
moving again today.
But this raised a question in my mind... how would I know if something had happened to my baby inside of me? I don't have a fetal heart monitor... which I think I may get even though I'm almost through with this pregnancy. But there must be physical signs that something has gone wrong. I mean, eventually, the body would have to get rid of the corpse... there must be physcial symptoms leading up to that, though. Does anybody know what those signs are?
I know this is a morbid topic... I'm sorry to depress anyone... but this is a very real concern, I think. I also think that a lot of very valid concerns are brushed away by doctors who start to take questions and concerns as personal attacks against their judgement and ability and say, "at some point you have to just trust us." So, while I'm at it, I'd like to comment on that note - pregnant women... particularly first-timers... have a TON of questions. All magazines and books and other people are asking us questions and encouraging us to learn more. And when we ask the people who (should) have the answers to our questions, I have found that many times they become weary and "draw the line" on questions after a short while and say "just trust us." Our questions are not a matter of mistrust! That is ridiculous! And I think that any mother-to-be who says to herself (LIKE I DID LAST NIGHT) 'oh, there's probably nothing wrong'... that's WRONG! I don't care how many times you question the safety of your baby during pregnancy, that is a BIG unknown, particularly to those of us who are not experts and know what signs to look for... and you COULD be right so you've GOTTA find out.
Thanks everybody!!!

Thank you all for responding!!!
Ummm... I know all that common knowledge about what else it could be... dropped? No. He's still up kicking my breast bone today. I meant when I said it felt like he went limp - he was leaning to one side, sort of, in a very UNusual way. I felt a LOT of pressure that woke me up in the middle of the night just under my left breast at the top of my belly. And it was very hard. Now I ruled out a contraction because it was concentrated on that one spot and it felt hard only at that spot... more like it was a part of his body pushing very hard underneath right there.
Tonight was my last night of lamaze classes and we talked about dropping... it definitely wasn't that.
See, there was that hard pressure at that one spot - his body must have been pushing right there while he was sleeping or something. And lately I've been subconsciously feeling him moving while I sleep and when I realized when I woke up with that pressure that I hadn't felt it at all that night, I started to get a little concerned.

I can't believe they tell a woman to wait TWENTY FOUR hours without feeling any movement to get concerned! I mean, I would think that would be WAY too long and by then making a call would be practically USELESS. For me something more like FOUR hours would be enough!

But my question really remains... I'm trying to keep perspective on the reality of this issue... how WOULD I know if something was really wrong? What symptoms would I feel other than those puzzling absences of movement and strange positioning?

Thank you all SO much for your advice! If anybody still might be able to inform me about what symptoms a woman who is losing her baby might feel, I still would like to know... if only to quench of my curiosity.

I really appreciate all of this comforting! Thanks so much!!!
But let me explain something about myself... I joined the Fire Department at the beginning of my pregnancy before I knew I was pregnant. And I am the kind of person who feels that anything a person can do to help save lives is worthwhile. I don't think we should ease our worries at the risk of "dropping it" when you have a feeling that COULD be right. ...But I definitely appreciate the consolation!
And my question is (more fine-tuned), basically, are there symptoms one would feel very immediately - early enough that if recognized, there would still be time to save the baby's life? And if so, what are they?
I know we need to rest our weary minds about things like this, but... sometimes I think I should have been a doctor... I NEED to know the answers to questions like that all of the time... and I don't have any problems discussing morbid topics like that. (Except when you hear stories like that lady who just drowned her five children in a fit of post-partum depression... that's the kind of presentation of a morbid topic that makes me want to lash out on the person that could do something like that. ...Or do some good old kickboxing! I miss that.)
Oh, and there was someone who said earlier that they'd never heard of the umbilical chord strangling a baby in utero... well, me neither... but it occurs to me that it seems quite conceivable.
Again, I really appreciate everyone's advice... please don't think that I'm driving myself crazy with this... I'm just seeking out the answer to this question... it's not bugging me in any extreme way... it's just something I REALLY would like to know.

P.S. I have TWO copies of "What To Expect When You're Expecting," one copy of "What to Expect The First Year," and one copy of "Your Baby's First Year." My take on "What To Expect When You're Expecting" is, first of all, that it covers A TON of topics and issues... essentially everything that most mothers think about at least at some point during their pregnancies and sometimes things they'd never think about. However, I find that the direction it leads you in is, yes there are all of these concerns, but most are really unlikely and you shouldn't worry about them. For me, it's too passive sometimes. I'm a "I want to know for sure" kind of person.

Oh, yeah... I forgot to say that I was planning on taking that advice! I will have to do that... I just have to make sure that I do my best to present the question in the most non-imposing way. I have an appointment Monday afternoon, so I'll wait until then since I've been in the clear with my worries for a couple/few days now.
And I believe you're absolutely right about this being the kind of information you can't find in any book! That would be too morbid and depressing a topic for a writer to address. It's almost political, in a way... how would you expect to find success in a book that makes people feel down? So I think they know that they can't go that route, ya know? And they probably just don't think of addressing it.
Everyone's been so comforting and helpful... I just want to say that again! I'll let you all know what I find out, just like Beth said.

Oh, thank you, Leslie!!!!!!!
That was wonderful! I definitely feel I should have called my doctor when I was having doubts.
Earlier on I took a course called "All About Infants" and at one point we talked about "baby snatchers" and it got my mind going a little. Being an Architect, my mind is always in the "how can this be done better?" gear. I knew that the hospital I had chosen had the best security system in the area - they don't just tag mother and child and check the tags frequently, they actually put a sensor on the baby's ankle that sounds an alarm if the baby is taken outside of the alarm system's boundaries.
But I thought, well, maybe they will also introduce me to the nurses that will be taking care of my baby and I when I get to the hospital so that I only have to worry about identifying a few nurses.
So at my next visit I presented this to my OB and he took it as though I was paranoid about the baby being stolen in the hospital. The approach he took would have been wonderful if I really had been paranoid about it, but I don't think that I was. And after a while he got frustrated because he was trying to get me to talk about my paranoia when I felt that I really wasn't paranoid.
Since then I've felt that I don't have the kind of relationship with them and we switched to the wrong foot from then on.
Well, thanks again! The abdominal pain seems to me like it makes perfect sense... and the bleeding.
Gotta go get to work.
Thank you, thank you, thank you!!!

Oh, I know all about the nurses' shift changes and everything... that's exactly what my doctor told me (after he psychoanalyzed me about paranoia ).
And I am relaxed... I think... even though I do come off sounding like I am very anxious and nervous.
Your words are so wonderful sounding! You have a very calming effect. Personally, I am most calmed knowing the facts.
I had the first of my weekly visits today and I was examined by the new midwife in the Office. (I interviewed this Doctor early in my pregnancy after I had been to my regular GYN and felt that relating to her just wasn't the same as I had remembered it had been. At that time it was Dr. Altman and one midwife, Allison.) She was very easy to talk to! First she did a strep culture, then she asked if I had any questions or anything to talk about. So I explained the incident that had occurred and how and why I had become concerned that he could have gotten strangled in the umbilical chord... how Steve and I had both been born with the umbilical chord wrapped around our necks......
She said 25% of babies are born with the umbilical chord around their necks - that's pretty common - but it's rare that it actually causes any problems.
She also said that in the uterus, the baby is constantly floating around like he is in outerspace and is always looping in and out of the umbilical chord - it's a constant, daily, hourly (and so forth) event, but it rarely tangles around the baby. And the reason is that the baby and the umbilical chord are so slippery that it is like a piece of spaghetti... if you tie it in a loop and let go, the spaghetti relaxes and opens up again because it is so slippery. She compared it to a piece of rope - since it is dry, if you tie a knot in the rope, it will stay knotted.
Then we talked about symptoms a woman might feel if the baby was actually in distress. She said you may or may not feel anything. So, apparently, there's a fair likelihood that you would feel nothing at all and that, unfortunately, is the way that things sometimes go.
Well, I don't know if I'm all the way on that board... that we should feel that it could happen and we wouldn't be able to do anything about it... but at least the information she gave me gave me enough insight to reassure me that the chances are that nothing will happen to my baby.

And, if anyone is also interested, I brought up the reality of a baby possibly drowning during water birth. (When I went to the hospital to meet with a woman to prepare for me to have a water birth, she told me that they had to warn me that there had been ONE incident where a baby had drowned during a water birth.) So the midwife said, did she also tell you how that happened? Of course, I said no. She said that when water births were new, experts believed that the baby could stay under water for any length of time and they would not take their first breath of air until they came out of the water (like being in the womb with the amniotic fluid). A baby is stimulated by the air hitting their skin to take their first breath. However they have determined since then that they are not only stimulated by the air, but if they stay under water long enough, they will try to take a breath. So they now have "the ten second rule" she told me... even though it usually does not take a whole ten seconds to bring the baby out of the water and onto the mother's chest.
She further explained that there is nothing to worry about when the baby's head is out of the uterus, but the rest of the body is still in the uterus because the lungs are still inside the mother's body and still acting as though they are in the womb (because they still are) AND because the lungs are compressed by the pelvis and vaginal area... they cannot expand their lungs.
In the uterus, babies do not breathe in the same way that we do. Their air sacs are compressed until they take their first breath. The lungs do practice the movement to prepare the baby to take its first breath (and subsequent breaths), but this is only a practice for the baby's body as braxton hicks are "practice contractions" for a mother almost due. The oxygen is taken in through the umbilical chord all the way through until the baby's body is completely outside of the uterus. And the few seconds that the baby is under water, but not in the uterus, they have the reflex to not try to breath... and they also are not stimulated quite yet.

Thanks everybody for all your help and advice and comforting! Now we all have some more food for thought.
Good luck to all of you with your little ones and unborn babies!